1. Field of the Invention
Aspects of the invention relate to a fuel cell, and more particularly, to a fuel cell cartridge having a residual fuel measuring unit and a method of measuring the residual fuel of a fuel cell system having the fuel cell cartridge.
2. Description of the Related Art
A fuel cell system includes a fuel cell main body where electricity is generated and a fuel cell cartridge supplying fuel to the fuel cell main body. To secure stability and reliability of the fuel cell system, fuel must be stably supplied from the cartridge to the fuel cell main body regardless of the state of the cartridge. To this end, the residual fuel in the cartridge needs to be accurately measured.
When the fuel cell system is portable, the environment surrounding the cartridge can frequently change. For example, the orientation, temperature, and/or vibration of the cartridge can frequently change while the fuel cell system is being operated. Even when the environment surrounding the cartridge changes frequently, the residual fuel in the cartridge needs to be accurately measured. In addition, since the accuracy and reliability of the fuel supply must be maintained, it is preferable that a fuel measuring operation not affect the fuel supply.
Also, when the residual fuel in the cartridge is accurately measured, the fuel cell system can be efficiently operated. For example, by accurately measuring the residual fuel in the cartridge, the time for replacing the cartridge can be accurately estimated and the fuel supply amount can be optimally controlled. For this purpose, the measured residual fuel in the cartridge needs to be transmitted in real time to a control portion of the fuel cell system. A unit for measuring the residual fuel in the cartridge needs to directly transmit a signal to the control portion of the fuel cell system.
Also, in terms of space efficiency, the cartridge needs to store as much fuel as possible in as small a volume as possible. The maximum volume of a fuel storage portion of the cartridge cannot be greater than the overall volume of the cartridge. Thus, it is important to minimize the volume of other portions of the cartridge excluding the fuel storage portion in the cartridge, such as the fuel supplying portion and the residual fuel measuring portion.
Although a variety of fuel cell systems have been introduced, most cartridges provided in the fuel cell systems hardly satisfy the above-described.